Functional printing is a category of printing that uses commercial printing equipment to print circuits or electronic devices which have a function other than or in addition to visual display of information. An example of printed circuits can be printing radio frequency identification (RFID) on a package or a product. Another example may be printing an electronic circuit on a package which is capable to produce a musical clip when the package is opened.
There are several approaches for printing functional patterns on substrates including direct printing of functional inks Other techniques use photolithography to mask and remove a pre-deposited functional layer.